Persistent cloudy weather left dozens of Mayor Wright Housing tenants without hot water for more than a month, thanks to insufficient or faulty backups to their solar water heaters.

Saipeti Lasaele, who has lived in the public housing complex for more than 20 years, said yesterday was the first time in more than six weeks that she had hot water.

"It was really, really bad," she said.

Wendall Chu, the public housing supervisor who manages Mayor Wright and two other projects, said the problem is that the water heating system is more than 20 years old. "It's old, and some of (the backups) may be completely defective by now," he said.

Although the problem is a recurrent one, this is the longest the tenants have been stuck with cold water, Chu said.

"We've never had rain like this before," Chu said. "It's unheard of. I've never experienced something like that."

Chu said his engineering section has been trying to come up with a solution to the problem, but is hindered by a lack of money. The backup heaters would cost $1,500 each to replace, and each of the 35 buildings needs two or three units.

In the meantime, Chu has recommended that the tenants heat water on the stove until the sun returns. "They grumble when I tell them to do that," he said.

Hanna Eliapo, the president of the residents association, said the problem was never fully explained.

"There's lots of excuses that I hear; we've got to wait for these men to come fix it," she said. "When it was raining, that was the worst ... but (it started) before the rain."

It's reached the point where many residents are so tired of going to the office, they don't even bother to complain, Eliapo said.

Lasaele said she has often had long spells with only cold water. "Sometimes, a whole month we don't have hot water," Lasaele said. "They just never come to fix it."

Rolf Christ, owner and operator of R&R Solar Supply who has worked on the Mayor Wright system, said the backup problems have been there from the beginning.

"The backup was misdesigned," he said. "It was way undersized."

Ideally, solar water-heating systems should have gas or electric backups that take over when there's no sun to heat the panels. The backups should provide at least a one-day supply of hot water.

At Mayor Wright, however, a backup unit that serves six households really only has the capacity to serve 1 1/2, Christ said.

Christ said what is happening at Mayor Wright is unusual for a building on a solar system. The only recent complaints he has received about other systems is when one needs to be reset to automatically switch to the backup heater when there isn't enough sun.

In the case of Mayor Wright, he said the complaints seem to focus on the backups, since they only seem to surface after days of cloudy weather.

"It's probably a good testimony (on solar power). If we do have regular weather, we don't seem to have a problem," he said.

Reach Treena Shapiro at tshapiro@honoluluadvertiser.com.